APRILIA ETX 150 Service Station Manual page 135

ETX - STX 150
Bleeding the braking system
Front
•
Any air trapped in the hydraulic circuit acts as a cushion, absorbing much of the pressure
applied by the brake pump and minimising the braking power of the calliper.
•
The presence of air is signalled by the "sponginess" of the brake control and poor braking
efficiency.
CONSIDERING THE DANGER FOR VEHICLE AND RIDER, IT IS STRICTLY NECESSARY, AFTER
REFITTING BRAKES AND RESTORING THE BREAKING SYSTEM TO ITS REGULAR USE CON-
DITIONS, THAT THE HYDRAULIC CIRCUIT BE AIR PURGED.
NOTE
THE VEHICLE MUST BE ON LEVEL GROUND TO BE PURGED. WHILE PURGING THE HYDRAUL-
IC SYSTEM, FILL THE RESERVOIR WITH THE NECESSARY QUANTITY OF BRAKE FLUID.
CHECK THAT, DURING THE OPERATION, THERE IS ALWAYS BRAKE FLUID IN THE RESER-
VOIR.
•
Remove the rubber protection cover
from the bleed valve
•
Insert the transparent plastic pipe in
the front brake calliper bleed valve and
slide the other end of this pipe in a con-
tainer to collect the fluid.
•
Remove the front brake fluid reservoir cap.
•
Quickly press and release the front brake lever several times and then keep it fully pressed.
•
Loosen the bleed valve 1/4 of a turn so that the brake fluid flows into the container. This will
release the tension on the brake lever and will make it reach the end of stroke.
•
Close the bleed valve before the lever reaches its end of stroke.
•
Repeat the operation until the fluid draining into the container is air-bubble free.
NOTE
Braking system
BRAK SYS - 135